To determine travel paths, Hall sensors, optical sensors and inductive systems are used. For example, DE 10 2007 008 155 A1 discloses a device for detecting relative movements of chassis components of a chassis, which comprises a signal emitter attached on a first chassis component and a signal receiver attached on a second chassis component that can move relative to the first chassis component, the signal receiver being designed such that the three-dimensional position of the signal emitter relative to the signal receiver can be determined. In this case the signal emitter comprises a magnet and the signal receiver a 3D Hall sensor.
The disadvantage of such a no-contact detection method is that its realization incurs considerable costs.